Formation Rate and Energy Yield of Hydroxyl Radicals in Water under the Action of Gas-Discharge Plasma

Abstract

The kinetics of hydroxyl radical formation in water under the action of a pulsed discharge in vapor-gas bubbles formed near the surface of a graphite electrode immersed into water is studied. The reaction of potassium hexacyanoferrate(II) oxidation is used to determine the concentration and formation rate of OH radicals in the liquid phase. The power dissipated in the discharge is estimated from measurements of the time dependences of the current through the discharge cell, the voltage applied to the electrodes, and the integrated intensity of the discharge radiation. The yields of OH radicals per 100 eV of the energy applied to the plasma are calculated. It is found that, with an increase in power from 13 to 100 W, the rate of radical generation increases within the range of (2.8–34.8) × 10–7 mol/(L s). The radical yield weakly depends on power and is equal to 0.12 ± 0.03 particles/100 eV.